This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The increased incidence of pediatric type 2 diabetes parallels increased prevalence of obesity. Obesity is commonly accompanied by insulin resistance and hyperinsulinemia, which precedes and plays a major role in the development of type 2 diabetes. This phenomenon may be related with the fact that American adolescents, especially girls, are now becoming less physically active in early puberty, explaining the largely pubertal and post-pubertal onset of type 2 diabetes in adolescents. Although regular physical activity has been suggested to attenuate obesity and prevent type 2 diabetes in high-risk children and adolescents, the magnitude of exercise training-induced improvement in the risk factors for type 2 diabetes has been only recently studied in adults and not studied in pediatric populations. The objectives of this study are: 1) to determine the effects of exercise on insulin sensitivity in insulin-resistant African-American and Hispanic adolescents and 2) to determine the effects of exercise on fibrinolytic markers in insulin-resistant African-American and Hispanic adolescents.